Abstract: An alarm system for use with vehicles having a part requiring a special security tool for attachment or removal includes a bracket for removably holding the tool in a storage position, a normally closed electric proximity switch which opens when the tool is in the storage position, and an electric alarm. The proximity switch and alarm are wired in a circuit which is energized only when the vehicle ignition switch is on. When the tool is away from its storage position, the proximity switch is closed, and the alarm alerts the driver of such fact when the vehicle ignition is turned on. A preferred system includes a permanent disc magnet mounted on the security tool, a magnetically actuated reed proximity switch, and a magnetic buzzer alarm, the permanent magnet and switch being mounted on the tool and bracket respectively in such locations that the magnet is within the actuation distance of the switch when the tool is in its storage position.